1070-4272/01/7402-0353 $25.00 C 2001 MAIK [Nauka/Interperiodica]
Russian Journal of Applied Chemistry, Vol. 74, No. 2, 2001, pp. 353!354. Translated from Zhurnal Prikladnoi Khimii, Vol. 74, No. 2, 2001,
Original Russian Text Copyright + 2001 by Lebedeva, Shaglaeva, Kanitskaya, Pirogova, Fedorov, Mikhaleva, Khaliullin.
Copolymerization of N-Vinyl-4,5,6,7-tetrahydroindole
O. V. Lebedeva, N. S. Shaglaeva, L. V. Kanitskaya, G. A. Pirogova, S. V. Fedorov,
A. I. Mikhaleva, and A. K. Khaliullin
Irkutsk Institute of Chemistry, Siberian Division, Russian Academy of Sciences, Irkutsk, Russia
Received June 6, 2000
Abstract-Radical copolymerization of N-vinyl-4,5,6,7-tetrahydroindole with acrylamide in dimethylform-
amide was studied, and the relative activity constants of the monomers were determined.
N-Vinylpyrroles are reactive monomers in both cat-
ionic and radical polymerization processes and allow
preparation of polymeric materials with a wide spec-
trum of valuable properties: special semiconductors,
photosensitive materials, flotation agents, biologically
active compounds, synthetic dyes, etc. .
In this work we studied the activity of N-vinyl-
4,5,6,7-tetrahydroindole (VTHI) in radical copolymer-
ization with acrylamide (AA).
Copolymerization of VTHI with AA in dimethyl-
formamide (DMF) yields cream-colored powders
soluble in DMF, DMSO, and N-methylpyrrolidone.
The IR spectra of these products show that they con-
tain units of both monomers (absorption bands of
the pyrrole ring at 1300, 1380, 1490, and 1540 cm
and those of acrylamide at 510 and 965 cm
) and no
double bonds (no bands at 859, 946, and 1585 cm
The copolymers are free from homopolymer impuri-
ties, which is confirmed by the smooth shape of the
turbidimetric titration curves.
C NMR spectra contain strongly broadened
signals from the carbon atoms of the VTHI and AA
fragments (ppm): 130.93125.3 (C
), 108.03105.8 (C
), 52.3347.8 (C
), 23.1319.0 (C
) and 180.03174.0 (C=O),
C NMR spectra, we calculated the mole
fractions of VTHI and AA and also the elemental
composition of the copolymers (see table). The mole
fraction of the VTHI units in the copolymer grows
with increasing fraction of VTHI in the initial mix-
ture, but does not exceed 0.4 even at the VTHI : AA
ratio in the initial mixture of 4 : 1. This fact is con-
sistent with the relatively low rates of radical poly-
merization of VTHI . For the system VTHI3AA,
the copolymerization constants are as follows: r
With the fraction of VTHI units in the copolymer
increasing by a factor of ~4, the viscosity of the prod-
uct grows twofold.
The copolymerization of the monomers was per-
formed in sealed ampules at 60oC in the presence of
azobis(isobutyronitrile) under argon. The reaction
mixture was dissolved in DMF, and the copolymer
was precipitated with acetone. Then the copolymer
was reprecipitated from DMF solution into acetone
and dried in a vacuum to constant weight. The in-
trinsic viscosity was determined in DMF at 20oCby
the dilution procedure.
The relative activity constants were calculated by
the Fineman3Ross and Kelen3Tudos procedures using
G.I. Deryabina’s program, with the Mortimer3Tidwell
experimental design. The calculations were based on
the results of experiments with conversion of <10%.
The IR spectra were taken on a Specord 75-IR spec-
trometer from KBr pellets or mulls in mineral oil.